点击事件与屏幕溢出判断

来源：互联网发布：手机如何查看淘宝粉丝编辑：程序博客网时间：2024/06/05 22:44

首先创建侦听事件：

<span style="white-space:pre"></span>auto listen = EventListenerTouchOneByOne::create();listen->onTouchBegan = CC_CALLBACK_2(Plane1::onTouchBegan, this);listen->onTouchMoved = CC_CALLBACK_2(Plane1::onTouchMoved, this);listen->onTouchEnded = CC_CALLBACK_2(Plane1::onTouchEnded, this);listen->onTouchCancelled = CC_CALLBACK_2(Plane1::onTouchCancelled, this);listen->setSwallowTouches(true);

然后为对象写上点击事件，判断对象是否在点上，写上方法：

<span style="color: rgb(255, 0, 0); white-space: pre;"></span>listen->onTouchBegan = [](Touch* touch, Event* event){auto target = static_cast<Sprite*>(event->getCurrentTarget());Vec2 locationInNode = target->convertToNodeSpace(touch->getLocation());       Size s = target->getContentSize();Rect rect = Rect(0, 0, s.width, s.height);if (rect.containsPoint(locationInNode)){return true;}return false;};

移动方法，判断点击后移动对象：

listen->onTouchMoved = [](Touch* touch, Event* event){}auto target = static_cast<Sprite*>(event->getCurrentTarget());      //获得对象getCurrentTarget();target->setPosition(target->getPosition() + touch->getDelta());    //偏移getDelta();Size visibleSize = Director::getInstance()->getVisibleSize();Point origin = Director::getInstance()->getVisibleOrigin();<pre name="code" class="cpp">}

在移动方法里写上屏幕大小的适配，目的就是防止对象移动到场景外：

/*X轴*/if (target->getPositionX() + touch->getDelta().x >= visibleSize.width - target->getContentSize().width / 2){target->setPositionX(visibleSize.width - target->getContentSize().width / 2);}else if (target->getPositionX() + touch->getDelta().x <= target->getContentSize().width / 2){target->setPositionX(target->getContentSize().width / 2);}else{target->setPositionX(target->getPositionX() + touch->getDelta().x);}/*Y轴*/if (target->getPositionY() + touch->getDelta().y >= visibleSize.height - target->getContentSize().height / 2){target->setPositionY(visibleSize.height - target->getContentSize().height / 2);}else if (target->getPositionY() + touch->getDelta().y <= target->getContentSize().height / 2){target->setPositionY(target->getContentSize().height / 2);}else{target->setPositionY(target->getPosition().y + touch->getDelta().y);}<span style="color:#ff0000;"></span>

首先target获取到点击的对象，然后判断它移动是否超出场景边界，当它超出边界时就默认它为最大边界，这样子就可以让它保持最大边界的极限值，从而达到效果。这里就是点击事件的代码，还有边界问题，有一些头文件的调用就在这里省略了，具体的方法可以去查看cocos的API，参照这里就知道它的具体使用。

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